Printing device components (e.g., platens or other components) may include ribs, rib structures, and/or similar features, upon which an image medium may be supported. A rib or series of ribs may, for example, support an image medium while ink nozzles, ink orifices, and/or other devices apply ink or other substances to the image medium to create an image on the image medium. An image medium may be supported by ribs rather than by a flat plate so that excess ink that is applied beyond the borders of image medium may be collected. Printing device components may also include ribs for convenience of design or for other reasons.
Ribs, however, may create areas of higher contact pressure with the image medium. The contact pressure may tend to be higher at discontinuities such as the start and end of ribs in the direction of motion of the print medium, and at the edges of the ribs perpendicular to the direction of motion. This effect may tend to be exacerbated by paper curl, manufacturing tolerances, and deliberate methods to control the shape (e.g., flatness, etc.) of the print medium.
Printing device components with ribs may be used in printers with borderless printing, duplex printing (e.g., double-sided printing), and/or other features. In duplex printing an image may be applied to one side of image medium, the image medium may be flipped or rotated, and ink may applied to a second side of the image medium. While ink is applied to the second side of the image medium, the ink recently applied to the first side of image medium may still be wet (e.g., un-dried). Un-dried or partially dried ink on an image medium may be more susceptible to scratching (e.g., removal or smearing) when the image medium comes into contact with ribs. Additionally, some image media are susceptible to scratching regardless of the presence of ink. The likelihood and/or severity of ink scratching and image medium scratching may vary with the contact pressure applied to the image medium. Contact pressure between two objects is generally inversely related to the size of contact area between the two objects. Contact between a flat sheet (e.g., an image medium) and sharp edges, sharp radius corners, and/or surfaces of small area may result in higher contact pressure than contact with smooth edges, large radius corners, curved surfaces defined by a large radius of curvature, smooth curved surfaces, and/or flat surfaces. Thus, a rib that supports an image medium on a smooth surface and/or large radius curved surfaces may reduce scratching to an image medium and ink and may, therefore, be desirable.
It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. Moreover, some of the blocks depicted in the drawings may be combined into a single function.